SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7e92c0959798af3d1ca99312a49f93251ff36e10e762351935d5f1a939b9afcf' 
  AND token = 'aXgLC2YOp5DqQy8trG/DtGQn71Tkxw2IDGQ9n1EsJqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}